Shearing-tool.



Patented I an. 8, A|901.

vnu. 655,553.

'.I. K. STEWART.

summe Tool.. (Application bd Apr. 16, 1900.) (llo Indsl.)

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PATENT -EE1CE.

JOHN K. STEWART, OF CHICAGO, ILLINOIS.

SHEARINfG-TOOL' SPECIFICATION forming part of Letters Patent No. 665,553, dated January 8, 190'1. Application led April 16, 1900. Serial No. 13,024. (No model.)

To a/ZZ whom it may concern:

Be it known that I, JOHN K. STEWART, a citizen of the United States, residing lat Chicago, county of Cook, State of Illinois, have invented certain new and useful Improvements in Shearing-Tools, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

This invention relates to the means (in a shearing-tool or clipper) for maintaining equal pressure between the cutters at all the several fingers or cutting points and in all points of oscillation; and it consists in specic improvements in the device for this purpose which are set out in the claims.

In the drawings, Figure 1 is alongitudinal vertical section of a shearing-tool having my improvements. Fig. 2'is a plan of the same with the cap-plate removed. Fig. 3 is a detail section at the line 3 3 on Fig. 1.

A is the body in which the operating parts are journaled and mounted and which carries rigid with it at the forward end the comb or fixed cutter B.

C is the operating-shaft, journaled in the handle A2 of the body and actuating the main lever D by the customary crank-pin and roll c, operating in the vertical channel D' at the rear end of the lever D. The lever D is fulcrumed on the post A3, rigid with the body A. At its forward end it terminates in the yoke or eye D2, through which the knife-actuating lever-arm E extends from the pressure-screw F, which is set through the rear end of said arm and stepped at fin the post A3 to the oscillating cutter G, which said lever-arm E engages by means of pins e e,which extend down from said lever-arm into said cutter just behind the bearing-points of the fingers E' E' of the lever-arm on the root's of the two extreme teeth G' G'.

H is a secondary lever, which is pivoted at h to the lever-arm E and extends forward under said arm, protruding between the lingers E E' and bearingon the middleV tooth G2 of the cutter G. A rigid pin H extends up from the lever H through the lever-arm E and bears at its upper end on the under side of the cross-bar of the yoke or eye D2.

J is a hardened-steel plate, which closes an aperture in the cap A immediately above the yoke or eye D2, said plate being held to the cap by the bolts j j, which hold the cap to the body, as seen in Fig. 3. The under surface of this plate is parallel with the plane of contact of the cutters, and the upper surface of the yoke or eye D2, where it bears on the plate, is designed to be in the same plane and is finished so as to move with minimum friction on said plate J as the lever-arm E oscillates. 1

L is a spring-dog that is attached to the lever-arm E and arranged to engage the ratchet at the periphery of the pressure-screw F.

It will be seen that by screwing down the pressure-screw F the rear end of the leverarm E is elevated, and the iingers E' E at the forward end, resting on the oscillating cutter G and pressing it on the iixed cutter B, cause an upward pressure at the pivot h of the lever H, which in this action has its fulcrum at the upper end of the pin H', resting against the under side of the yoke or eye D2, and is thus thrust down at the forward end on the cutter G. The relative positions of the pivot h of the pin H', stepf of the pressure-screw F, and the fingers E' E are such that thel pressure on the three teeth ot' the cutter G which are pressed upon, respectively, by the fingers E' E' of the lever-arm E and by the terminal linger of the lever H is substantially equal upon the xed cutter or comb B. It is designed that the two cutters shall be held together with a substantially unyielding or inelastic pressure, and the pressure-screw F is designed to be adjusted so as to cause this perfect contact and barely-perceptible pressure without springing the parts, so as to cause any tendency of the'cutter-teeth G' G' and G2 of the oscillating cutter to spring down between the cutter-teeth of the fixed cutter or comb B, as they might do under an elastic pressure, by reason of the slightly-hollow contour of said'cutter-teeth. (Not'perceptible in the drawings.) When such elastic pressure is used, either the cutters are held together with such slight pressure that a hair or wool fiber frequently is entered between them, so as to hold them apart, thus destroying their power to cut reliably, or if the pressure is too great to permit such an occurrence it causes the teeth of the oscillating cutter to spring down between the teeth of IOC In the construction above describedall the parts by which the pressure is transmitted to the cut-ters are as rigid as possible and the lIo distance between the bearing-points as short as possible, so that the spring of the parts is reduced to a minimum, and by this means, although at the point at which the pressure reacts against the case-that is,where the top ot' the yoke or eye D2 bears upon thevund'er side of the plate J-the construction necessitates sliding friction, a very easy action is obtained and one which causes the minimum wear at the plate J. By arranging this plate to be applied from the outside of the cap and to be a detachable piece susceptible of being thoroughly iinished and hardened this bearing is made very easy to keep in order. An especial advantage of the structure at this point arises from the fact that the bearingsnrface for the main leve'r upon the case faces downward, so that it is not liable to accumulate dust and dirt and hairs, which would interfere with the action and cause the plate to be cut away. It will be understood that all parts which bear upon the oscillating cutter have opportunity to rock at the step-bearingf of the pressure-screw Fin the upper end of the post A3, so that the cutter is accommodated in all parts of its movement to the upper part of the fixed comb.

I claiml. In a clipper or shearing-tool, in combination with a case or body, the lever-arm for operating the oscillating cutter having an upwardly-facin g bearing-su rface, the upper wall or cap of the case having an aperture above such bearing-surface, and a detachable plate applied at such aperture and having its lower face in a plane parallel to the plane of contact of the cutters and arranged to afford bearing for said upwardly-facing surface of the lever.

2. In a clipper or shearing-tool, in combination with the oscillating cutter and the main operating-lever, a lever-arm carried by said main lever having vertical pivotalaction thereon, and bearing on the oscillating cutter, and constituting the medium by which the main lever actuates said cutter; a screw operating in said arm and against a part rigid with the case at the axis of the pivot of said main lever, the latter having an upwardlyfacing bearing-surface, and the case'having a plate with a bearing-surface parallel with the plane of contact with the cutters, against which the bearing-surface of the main lever is pressed by the action of the screw forcing the cutters into contact.

3. In a clipper or shearing-tool, in combi'- nation withthe bodyV or case,th'ef oscillating cutter, the main lever fulcrumed on a post l. rigid Ywith the case and having forward of such fulcrum a yoke or eye, a lever-arm extending through suchl yoke or eye and bearing at "its forward end upon and actuating the oscillating cutter; and a screw stepped on saidpost and operating in the lever-arm; the

lupper wall or cap of the case having a bearplemental lever pivoted to said lever-arm and extending forward between said fingers of the latter and bearing at its forward end on the cutter intermediate the bearing of said fingers thereon; said supplemental lever having a projection forward of its pivot extending against the underside of the cross-bar of the eye or yoke of the main lever; and a pressure-screw operating in the rear end of the lever-arm and stepped on the fulcrum-post at the axis thereof.

5. In a clipper or shearing-tool, the body or case, the main operating-lever therein fulcrumed on a post rigid with the case and having forward of such fulcrum a yoke or eye; a lever-arm extending through such leverarm and bearing at its forward end on and engaging the oscillating cutter; an adjustingscrew'set through the lever-arm and stepped upon the fulcrnm-post at the axis; a supplemental lever pivoted to the lever-arm back of the yoke or eye and at its forward end bearing at substantially the middle point of the oscillating cutter, and having a pin extending through the lever-arm without engagement therewith against theunder side of the cross-bar of the yoke, the top or cap of the case having an aperture over the yoke or eye, andan :eXteriorly-applied bearingplate 4covering saidaperture and receiving the upward pressure of the main lever.

In testimony whereof I have hereunto set my hand, in the presence of two witnesses, it Chicago, Illinois, this 14th day of April, A. D.

JOHN K. STEWART.

In presence of- CHAS. S. BURTON, ADNA H. BOWEN, Jr.

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